I am trying to set up an outdoor theater with a ~150" wide image. Assuming that the movie watching will be happening after sunset, what kind of lumens should I be looking for in the projector? There is still going to be some ambient light, this is for neighborhood events in an outdoor space. Do I need to be looking at high gain screens? Our budget is around $5k, but if that won't get me a decent picture than I may be able to expand it.